(1) Field of the Invention
This invention generally relates to a device for enabling a quiet ejection of launched items from a launch tube. More particularly, the invention relates to piston deceleration system utilizing an arrangement and shape of bumpers and a modified piston shaft.
(2) Description of the Prior Art
The current art for submarine launch systems for three inch devices was developed in the early 1960""s. The launch systems utilize a basic design as shown and described in connection with FIGS. 1A-1C, hereinbelow. Because these systems create a cavitation or water hammer during launch, they are incapable of conducting a quiet launch.
Thus, a problem exists in the art whereby it is necessary to remove the cavitation or water hammer effect in order to produce a quiet launch.
The following patents, for example, disclose various types of piston control, but do not disclose an arrangement and shape of pistons or shaft as does the present invention which permits a quiet launch.
U.S. Pat. No. 4,561,248 to Quin et al.;
U.S. Pat. No. 4,609,135 to Elliesen;
U.S. Pat. No. 5,224,413 to Herner; and
U.S. Pat. No. 5,850,776 to Takeuchi et al.
Specifically, Quin et al. disclose a hydraulic shock-absorbing jack particularly for use underwater which includes a cylinder in which a piston associated with an actuated rod is slidable. The piston defines within the cylinder a first actuating chamber provided with a first inlet for actuating liquid and connected to an accumulator of elastically variable volume, and a second actuating chamber provided with a second inlet for actuating liquid. The rod is mounted to be slidable relative to the piston such that, in the event of a shock applied to the rod which would otherwise cause an increase in the volume of the second chamber, the rod alone moves relative to the piston without affecting the volume of the second chamber. The rod is provided with an enlarged head located in the first chamber and preventing its disengagement from the piston.
The patent to Elliesen discloses a sound-dampened driving apparatus for fasteners wherein a main valve means is arranged above a working cylinder of the apparatus and movable within a cylindrical bore. When the main valve means is in its lower at rest position, the main valve means separates the working cylinder from a source of compressed air and connects the cylinder to the atmosphere. When the main valve means is in its upper actuating position, the working cylinder is connected to the source of compressed air and the valve means blocks the cylinder connection to the atmosphere. The space above the main valve member within the cylindrical bore is capable of being alternately connected to either the atmosphere or compressed air, and includes a sound dampening means arranged in the space above the main valve member.
Herner discloses an impact dampening ring having a primary bumper and a secondary bumper for dampening the engagement of a piston against and end of a power cylinder. The primary bumper has a curved or arcuate surface for initial engagement with the end of the cylinder and the secondary bumper has a flat surface for secondary engagement with the end of the cylinder. The engagement of the primary and secondary bumpers dampens the impact and prevents the piston from directly engaging the end of the power cylinder. A mounting flange on the impact dampening rings provides a means for mounting the impact dampening ring onto a mounting surface of the piston. A seal along the outer perimeter of the impact dampening ring provides a fluid tight seal for the piston inside of the power cylinder.
Takeuchi et al. disclose a fluid pressure cylinder including a cylinder body, a piston accommodated in the cylinder body to define first and second pressure chambers therein, means for supplying fluid to each chamber to reciprocate the piston between a first stroke end and a second stroke end, first and second bumper surfaces, an annular cushion retainer connected to the first bumper surface, and an elastomeric cushion for deforming and cushioning an impact produced when the piston reaches the first stroke end. The bumper surfaces approach each other when the piston reaches the first stroke end and separate from one another when the piston moves toward the second stroke end. The cushion has a shape corresponding generally to a hollow conical section. The cushion includes a base section retained by the cushion retainer and a buffer section joined to the base section. The buffer section has an outer surface for contacting the second bumper surface and an inner surface that faces the first bumper surface. The outer surface forms a circular seal with the second bumper surface when the piston approaches the first stroke end. The cushion is flexed such that the buffer section moves toward the first bumper surfaces. The buffer section moves away from the first bumper surface when the piston moves towards the second stroke end.
It should be understood that the present invention would in fact enhance the functionality of the above patents by providing both a unique arrangement and shape of shock absorbing members within a launcher impulse tank assembly and structuring the piston assembly itself to aid in the shock absorption of the piston stroke.
Therefore it is an object of this invention to provide a piston deceleration system for absorbing a piston shock at one end of the stroke.
Another object of this invention is to provide a piston deceleration system utilizing a unique arrangement of deflection bumpers for reducing shock within an impulse tank assembly.
Still another object of this invention is to provide a piston deceleration system utilizing a unique shape of deflection bumpers that prevents cavitation within an impulse tank assembly.
A still further object of the invention is to provide a piston deceleration system which is integrated into existing piston systems without substantial modification.
Yet another object of this invention is to provide a piston deceleration system which is simple to manufacture and easy to use.
In accordance with one aspect of this invention, there is provided a piston deceleration system including an elongated piston shaft, a piston member slidably seated on the elongated piston shaft, a tank member having a first opening formed in a first end surface thereof and a second opening formed in a second end surface thereof, the elongated piston shaft being reciprocally inserted into the tank member through the first end surface. An intermediate stop limit member is formed on the elongated piston shaft between the piston member and the first end of the tank member. A shaft shock absorbing member is positioned between the stop limit member and the piston on the elongated piston shaft, and a piston shock absorbing members is positioned between the piston member and the second end of the tank member on the elongated piston shaft. Each of the plurality of shock absorbing members absorbing a shock of the reciprocating piston member.